Lots Of Little Credit Charges Add Up To One Big ScamFraudsters know that small credit transactions often go unnoticed. That's made it easy for a widespread scam involving unauthorized charges of $9.84 to fly under the radar. Complaints started coming in about the scam soon after a massive data breach in November, but analysts say it goes back months.

Would you notice an unexpected charge of $10 or less on your credit card statement? Lots of consumers don't — and scammers count on that, says Steve Barnas, president and CEO of the Better Business Bureau in northern Illinois.

How To Protect Yourself

Data thieves are becoming more sophisticated, making it more difficult for law enforcement to investigate and combat scams. But there are some things you can do to help prevent fraudulent use of your credit card. Here are some useful tips:

Don't share your account number with anyone over the phone unless you initiated the call and you know the company is reputable.

Do your homework before sharing account information with an unfamiliar business or website. The FBI has some detailed suggestions for conducting due diligence. Also search online for any reviews, complaints or alerts.

Don't provide your account information or personal data in response to any unsolicited email, Facebook messages or tweets from financial institutions. Use the phone number on your card to contact the institution directly to verify any unexpected contact.

Be aware of your surroundings when reading your credit card aloud over the phone. Anyone can take down your information and use your card fraudulently.

Look for skimming devices or other signs of tampering, like glue, loose components or scuff marks, before using an ATM, particularly one in low-traffic areas.

Don't access online banking sites on public Wi-Fi networks, which are vulnerable to hackers.

Carry your credit cards and wallet separately. Carry only the card you need for a particular occasion.

Keep your credit card in sight during a transaction and always double-check that it was returned before leaving.

Don't sign blank receipts; scammers can fill in false totals. Draw a line though any blank spaces above the receipt's "total" field.

But Barnas says the Better Business Bureau is now hearing from consumers across the country about $9.84 credit charges for what look to be very innocuous purchases. But while they may seem legitimate, many are not.

"Most of them we're seeing say "customer support" [or] "website support," he says. "And basically [what] they are really trying to do is get really pedestrian, in essence, so it flies underneath the radar."

And there's another reason why some consumers may ignore small charges, Barnas says. "Usually if it's a joint credit card, the husband thinks the wife charged it and the wife thinks the husband charged it."

Lois Greisman, associate director of Marketing Practices at the Federal Trade Commission, says this is an old and clever scam.

The precise amount, $9.84, "makes you think you actually purchased something," she says.

"The idea of illegally putting unauthorized charges on somebody's credit card statement and doing it in a particularly low amount that's not likely to jump off the sheet — assuming anyone's even reading it in the first place — is a fairly known tactic by scammers," Greisman says.

No one's sure how big this particular con is, but after complaints starting piling up on website forums, Brian Krebs of KrebsonSecurity.com began investigating. He doesn't think the $9.84 scam is tied to the recent data breaches at Target or other big retailers.

"When I look back at the domain names and the different website names and so on that were involved, it was pretty clear this has gone back many, many months before Target, and that this operation had just been going on for quite some time," Krebs says.

Krebs says the fraudsters hired call centers in India and set up websites that were fronts to look legitimate.

Barnas says that's why scam artists who steal credit card numbers hope consumers will overlook small charges. "Because they can change it from $9.84 to $20 tomorrow," he notes.

If you notice a problem, he suggests you call the credit card company right away for a new card.

And the FTC's Lois Greisman has some common-sense advice: "There's no substitute for reading line-by-line your credit card statement," and making sure that any charges — especially small ones — were actually made by you.